My understanding is that only James McNeil uses that term.
It came from a subset of the Five Families, Mok Gar (sometimes called Monk Fist Boxing because it was taught only to monks who guarded the gates). It was described as "hands of the snake and feet of the rat". Meaning it was very fast strikes to vital points and shuffling footwork done in close for power and adjustments.
As most things in the US, it was blended with other kung fu through GM Ark Wong by Haumea "Tiny" Lefiti and passed on with his prior martial arts training and fighting experiences.
"Browns" is the name given to the basic and advanced combinations taught as the foundation of the system. For the life of me, I can't remember how they got that name. But, in training them they were a generic template that would be executed in various ways as you advanced and depending on the attack. There were at least 10 variations on each one.
The information about the "browns" came from a Dr. Carl Totton article I came across on the internet. Dr. Totton was one of only 8 people to actually be given a rank certificate in his kung fu art.
